Abstract Body: Background:Stroke is the second leading cause of death worldwide, accounting for approximately eleven percent of all deaths. Effective prevention depends on early identification of at-risk individuals and clear communication of modifiable risk factors. Traditional risk calculators often lack transparency and adaptability for diverse clinical settings. Advances in artificial intelligence now allow integration of machine learning and natural language generation to enhance both prediction accuracy and patient communication. Therefore, we investigated the use of machine learning and LLM-based natural language generation to evaluate stroke risk prediction performance and the effectiveness of model-driven patient communication.

Methods: A dataset of 5,110 patient records containing demographic, behavioral, and clinical variables such as age, hypertension, heart disease, body mass index, glucose level, and smoking status was analyzed. Multiple machine learning algorithms (logistic regression, decision tree, random forest, gradient-boosted trees) were trained and compared for stroke prediction. Model interpretability was assessed using SHAP-based feature attribution to identify key predictors. Large language models (e.g., GPT, Claude, Gemini) were used to generate patient-friendly explanations, providing reasoning and context alongside predictions. Semantic consistency and differences across LLM explanations were compared. A mobile-responsive prototype tool was developed, allowing participants to enter individual variable values and receive risk prediction and interpretive feedback via QR code.

Results: Random Forest achieved the highest performance with 97% accuracy, 97% precision, 97% recall, and 97% F1-score, followed by Decision Tree (94% accuracy, 94% precision, 94% recall, 94% F1-score), Voting Classifier (91% accuracy, 91% precision, 91% recall, 91% F1-score), and Logistic Regression (87% accuracy). Feature attribution highlighted the most influential clinical and behavioral predictors. LLMs successfully generated individualized, understandable explanations of predicted risk, enabling patients to grasp modifiable factors. Comparative analysis of LLM outputs revealed subtle differences in reasoning and communication style.

Conclusions:This work presents an explainable and accessible stroke prediction framework combining machine learning and LLMs. This approach enhances patient engagement, promotes early intervention, and supports equitable stroke prevention.